Fluid couplings for vehicles conventionally use interleaved disks housed in a chamber containing a highly viscous fluid. Examples of such couplings are described in U.S. Pat. Nos. 4,650,028 and 5,117,937. These devices have several disadvantages. For example, they are often large in size and complex in configuration. The present invention is advantageous in that it avoids the complexity and size restraints of fluid couplings based on interleaved discs.